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SNMP device monitoring with Netdata

Collects data from any SNMP device and uses the gosnmp package.

It supports:

  • all SNMP versions: SNMPv1, SNMPv2c and SNMPv3.
  • any number of SNMP devices.
  • each SNMP device can be used to collect data for any number of charts.
  • each chart may have any number of dimensions.
  • each SNMP device may have a different update frequency.
  • each SNMP device will accept one or more batches to report values (you can set max_request_size per SNMP server, to control the size of batches).

Configuration

Edit the go.d/snmp.conf configuration file using edit-config from the Netdata config directory, which is typically at /etc/netdata.

cd /etc/netdata # Replace this path with your Netdata config directory
sudo ./edit-config go.d/snmp.conf

The configuration file is a list of data collection jobs. Jobs allow you to collect values from multiple sources, each source will have its own set of charts.

Generally the format is:

jobs:
- name: name1
... # other configuration parameters
- name: name2
... # other configuration parameters
- name: name3
... # other configuration parameters

Job configuration parameters

ParameterDefault valueDescription
name-the data collection job name
update_every10the update frequency for each target, in seconds
hostname127.0.0.1the target ipv4 address
communitypublicSNMPv1/2 community string
options.version2SNMP version
options.port161the target port
options.retries1the number of retries to attempt
options.timeout10the timeout for one SNMP request/response
options.max_request_size60the maximum number of oids allowed in one one SNMP request
user.name-the SNMPv3 user name
user.level-the security level of SNMPv3 messages
user.auth_proto-the authentication protocol for SNMPv3 messages
user.auth_key-the authentication protocol pass phrase
user.priv_proto-the privacy protocol for SNMPv3 messages
user.priv_key-the privacy protocol pass phrase
charts[]the list of charts
charts.id-is used to uniquely identify the chart
charts.titleUntilted chartthe text above the chart
charts.unitsnumthe label of the vertical axis of the chart
charts.familycharts.idthe name of the dashboard submenu under which each chart will be displayed
charts.typelinethe chart type (one of line, area or stacked)
charts.priority70000the priority of the chart as rendered on the web page
charts.multiply_range[]is used when you need to define many charts using incremental OIDs
charts.dimensions[]the list of chart dimensions
charts.dimensions.oid-the OID path to the metric you want to collect
charts.dimensions.name-the name of the dimension as it will appear at the legend of the chart
charts.dimensions.algorithmabsolutethe dimension algorithm (one of absolute, incremental)
charts.dimensions.multiplier1the value to multiply the collected value, applied to convert it properly to units
charts.dimensions.divisor1the value to divide the collected value, applied to convert it properly to units

Example: Using SNMPv1/2

In this example:

  • the SNMP device is 192.0.2.1.
  • the SNMP version is 2.
  • the SNMP community is public.
  • we will update the values every 10 seconds.
  • we define 2 charts bandwidth_port1 and bandwidth_port2, each having 2 dimensions: in and out.

SNMPv1: just set options.version to 1.

If you have multiple devices see how to simplify the configuration.

jobs:
- name: switch
update_every: 10
hostname: "192.0.2.1"
community: public
options:
version: 2
charts:
- id: "bandwidth_port1"
title: "Switch Bandwidth for port 1"
units: "kilobits/s"
type: "area"
family: "ports"
dimensions:
- name: "in"
oid: "1.3.6.1.2.1.2.2.1.10.1"
algorithm: "incremental"
multiplier: 8
divisor: 1000
- name: "out"
oid: "1.3.6.1.2.1.2.2.1.16.1"
multiplier: -8
divisor: 1000
- id: "bandwidth_port2"
title: "Switch Bandwidth for port 2"
units: "kilobits/s"
type: "area"
family: "ports"
dimensions:
- name: "in"
oid: "1.3.6.1.2.1.2.2.1.10.2"
algorithm: "incremental"
multiplier: 8
divisor: 1000
- name: "out"
oid: "1.3.6.1.2.1.2.2.1.16.2"
multiplier: -8
divisor: 1000

Example: Using SNMPv3

To use SNMPv3:

  • use user instead of community.
  • set options.version to 3.

The rest of the configuration is the same as in the SNMPv1/2 example.

If you have multiple devices see how to simplify the configuration.

jobs:
- name: switch
update_every: 10
hostname: "192.0.2.1"
options:
version: 3
user:
name: "username"
level: "authPriv"
auth_proto: "sha256"
auth_key: "auth_protocol_passphrase"
priv_proto: "aes256"
priv_key: "priv_protocol_passphrase"

SNMPv3 message authentication and privacy configuration options

The security of an SNMPv3 message as per RFC 3414 (user.level):

String valueInt valueDescription
none1no message authentication or encryption
authNoPriv2message authentication and no encryption
authPriv3message authentication and encryption

The digest algorithm for SNMPv3 messages that require authentication (user.auth_proto):

String valueInt valueDescription
none1no message authentication
md52MD5 message authentication (HMAC-MD5-96)
sha3SHA message authentication (HMAC-SHA-96)
sha2244SHA message authentication (HMAC-SHA-224)
sha2565SHA message authentication (HMAC-SHA-256)
sha3846SHA message authentication (HMAC-SHA-384)
sha5127SHA message authentication (HMAC-SHA-512)

The encryption algorithm for SNMPv3 messages that require privacy (user.priv_proto):

String valueInt valueDescription
none1no message encryption
des2ES encryption (CBC-DES)
aes3128-bit AES encryption (CFB-AES-128)
aes1924192-bit AES encryption (CFB-AES-192) with "Blumenthal" key localization
aes2565256-bit AES encryption (CFB-AES-256) with "Blumenthal" key localization
aes192c6192-bit AES encryption (CFB-AES-192) with "Reeder" key localization
aes256c7256-bit AES encryption (CFB-AES-256) with "Reeder" key localization

Example: Using charts.multiply_range option

If you need to define many charts using incremental OIDs, you can use the charts.multiply_range option.

This is like the SNMPv1/2 example, but the option will multiply the current chart from 1 to 24 inclusive, producing 24 charts in total for the 24 ports of the switch 192.0.2.1.

Each of the 24 new charts will have its id (1-24) appended at:

  • its chart unique id, i.e. bandwidth_port_1 to bandwidth_port_24.
  • its title, i.e. Switch Bandwidth for port 1 to Switch Bandwidth for port 24.
  • its oid (for all dimensions), i.e. dimension in will be 1.3.6.1.2.1.2.2.1.10.1 to 1.3.6.1.2.1.2.2.1.10.24.
  • its priority will be incremented for each chart so that the charts will appear on the dashboard in this order.

If you have multiple devices see how to simplify the configuration.

jobs:
- name: switch
update_every: 10
hostname: "192.0.2.1"
community: public
options:
version: 2
charts:
- id: "bandwidth_port"
title: "Switch Bandwidth for port"
units: "kilobits/s"
type: "area"
family: "ports"
multiply_range: [1, 24]
dimensions:
- name: "in"
oid: "1.3.6.1.2.1.2.2.1.10"
algorithm: "incremental"
multiplier: 8
divisor: 1000
- name: "out"
oid: "1.3.6.1.2.1.2.2.1.16"
multiplier: -8
divisor: 1000

Multiple devices with a common configuration

YAML supports anchors. The & defines and names an anchor, and the * uses it. <<: *anchor means, inject the anchor, then extend. We can use anchors to share the common configuration for multiple devices.

The following example:

  • adds an anchor to the first job.
  • injects (copies) the first job configuration to the second and updates name and hostname parameters.
  • injects (copies) the first job configuration to the third and updates name and hostname parameters.
jobs:
- &anchor
name: switch
update_every: 10
hostname: "192.0.2.1"
community: public
options:
version: 2
charts:
- id: "bandwidth_port1"
title: "Switch Bandwidth for port 1"
units: "kilobits/s"
type: "area"
family: "ports"
dimensions:
- name: "in"
oid: "1.3.6.1.2.1.2.2.1.10.1"
algorithm: "incremental"
multiplier: 8
divisor: 1000
- name: "out"
oid: "1.3.6.1.2.1.2.2.1.16.1"
multiplier: -8
divisor: 1000
- <<: *anchor
name: switch2
hostname: "192.0.2.2"
- <<: *anchor
name: switch3
hostname: "192.0.2.3"

Data collection speed

Keep in mind that many SNMP switches and routers are very slow. They may not be able to report values per second. go.d.plugin reports the time it took for the SNMP device to respond when executed in the debug mode.

Also, if many SNMP clients are used on the same SNMP device at the same time, values may be skipped. This is a problem of the SNMP device, not this collector. In this case, consider reducing the frequency of data collection ( increasing update_every).

Finding OIDs

Use snmpwalk, like this:

snmpwalk -t 20 -O fn -v 2c -c public 192.0.2.1
  • -t 20 is the timeout in seconds.
  • -O fn will display full OIDs in numeric format.
  • -v 2c is the SNMP version.
  • -c public is the SNMP community.
  • 192.0.2.1 is the SNMP device.

Troubleshooting

To troubleshoot issues with the snmp collector, run the go.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn't working.

  • Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that's not the case on your system, open netdata.conf and look for the plugins setting under [directories].

    cd /usr/libexec/netdata/plugins.d/
  • Switch to the netdata user.

    sudo -u netdata -s
  • Run the go.d.plugin to debug the collector:

    ./go.d.plugin -d -m snmp

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